Katsu Naito's shot of a Manhattan sex worker, from his book West Side Rendezvous.

This picture, called Meat Market, was taken in the meatpacking district of Manhattan in the summer of 1990, back when the area was dangerous. By day it was very quiet: I never saw anyone hanging out there except for the transvestite and transexual prostitutes, like this one, and their buyers. It only got busy late at night when people went to work in the meatpacking factories, or visited the nightclubs. These days it's trendy – the street culture has disappeared.

I was 27 and living in Harlem. I had lost a lot of friends to Aids, but these prostitutes were risking their lives daily for very little money. I wanted to know why, to understand where they were coming from, so I decided to shoot this project. I started going to the area every day, so the prostitutes could get comfortable with me. We would talk, have a coffee, get to know each other and, after a while, I could just capture who they were.

I don't remember this woman's name, and I never saw her again after this picture, but there was something about the way she was in that daylight, on the street and on the job, carrying a bag of crisps, just munching and walking. She knew my face so was like, "Sure, what can I do for you?" when I finally asked if I could photograph her.

In this image you can see the whole area. You can feel the temperature, see the graffiti and get a real sense of where she's at. Yes, it is vulnerable and sexual, but also very natural. Her G-string was slipping out. I liked her expression and the way she stood, almost like a horse.

I don't like to take lots of pictures; this was one of three. I didn't like carrying a camera bag. Maybe because I was giving out the sign, "Fine, go ahead and attack me, take my camera," no one ever did. It was risky and dangerous, but I was OK.